Electromagnetic buzzer for a watch with tongue adjustment means

ABSTRACT

A buzzer for a watch has an electromagnet system attached to a support arm, one end of which can be fixed in the watch and the other, free end of which can be adjusted relative to a membrane with a first adjusting element which is in a contacting relationship with the watch. The buzzer has a tongue, clamped tightly on one side, which can be excited to oscillate by the electromagnet system and which strikes against the membrane either directly or indirectly. The location of the tongue relative to the electromagnet system is adjustable by means of a second adjusting element acting on it in the vicinity of the tightly clamped end of the tongue.

United States Patent [1 1 [111 3,863,437

Barth et al. Feb. 4, 1975 [54] ELECTROMAGNETIC BUZZER FOR A 3,462,943 8/1969 Spadini et al. 58/575 [75] Inventors: Mandred Hans Barth, Calmbach;

Adolf Sedlak, Pforzheim; Walter E. Sodler, Buchenbronn, all of [57] ABSTRACT Germany [73] A i Ti x Corporation, W t b A buzzer for a watch has an electromagnet system at- Conn. tached to a support arm, one end of which can be fixed in the watch and the other, free end of which [22] Wed: June 1974 can be adjusted relative to a membrane with a first ad- [21] Appl, N 479,713 justing element which is in a contacting relationship with the watch. The buzzer has a tongue, clamped tightly on one side, which can be excited to oscillate [30] Fol-mg Apphcauon Pnomy Data by the electromagnet system and which strikes against July 5, 1973 Germany 2334153 the membrane eitherdirectly or indirectly The loca. tion of the tongue relative to the electromagnet system U-S. Cl. is adjustable means of a second adjusting element Int. Cl. acting on it in the vicinity of the clamped end of Search of the tongue [56] References Cited I 15 Claims, 4 Drawing Figures UNITED STATES PATENTS 2,786,326 3/1957 Junghans et al. 58/575 WATCH WITH TONGUE ADJUSTMENT MEANS Primary Examiner-George H. Miller, Jr.

SHEEI 10F 4 on mm mm B .3 cm 8 a 3 3 Q 8 mm 8 8 mm 5 mm 2 9 F ow ELECTROMAGNETIC BUZZER FOR A WATCH WITH TONGUE ADJUSTMENT MEANS BACKGROUND OF THE INVENTION The present invention relates to an improved electromagnetic buzzer for a watch, having a membrane, especially in the form of the watch crystal. More particularly it relates to an improved adjustment system for the buzzer.

An electromagnetic buzzer of the type mentioned at the outset for a wristwatch is already known from US. Pat. No. 3,462,943 issued Aug. 26, I969. In this buzzer, the tongue oscillates at right angles to, and strikes, a pin formed to the watch crystal and extending through the dial of the watch, whereby the watch crystal is to be excited in its natural frequency. Between support arm and tongue, the buzzer has a block which is mounted to a movement plate and to which the fixed ends of the support arm and the tongue are attached. Since it is necessary to adjust the buzzer, and especially its tongue, relative to the pin formed to the watch crystal, an adjustable yoke, attached in the watch, extends over the support arm in the area of the block and is in a contacting relationship with the support arm by means of a blade. Tightening the yoke causes the support arm to press against the pin, which however necessitates also moving the block toward the pin. Located in a tapped hole in the block at right angles to the plane of the tongue is an adjusting screw, whose one conical end is in a contacting relationship with the tongue in the vicinity of the clamping point and whose other end extends through a hole in the support arm in order to permit it to be rotated. This adjusting screw permits the tongue to be adjusted relative to a pole surface of a electromagnet of the electromagnet system facing it, which is also necessary.

The known design has various disadvantages: The tongue cannot be adjusted relative to the electromagnet system prior to installation of the buzzer in the watch, since the location of the tongue relative to the electromagnet system is altered during the adjustment of the buzzer relative to the pin on the watch crystal, which is necessary after installation. As a result of tightening the yoke which extends over the support arm in the area of the block, the location of the block also changes, and with it the location of the adjusting screw; however the change in location of the electromagnet system is greater than that of the tongue, so that the gap between an anchor sheet fixed to the tongue and the electromagnet system is altered.

A further disadvantage is that, as a result of the contacting relationship of the adjusting screw in the direct vicinity of the firmly clamped end of the tongue, :1 very slight rotation of the adjusting screw results in large alteration of the gap between tongue and electromagnet system. Finally, during operation the tip of the adjusting screw, which is in a contacting relationship with the tongue, is permanently deformed, whereby the gap between tongue and electromagnet system is also altered during the course of time. Since, finally the above mentioned yoke is also in a contacting relationship in the vicinity of the fixed end of the support arm, relatively minor changes in position of the yoke result in a relatively great change of position of the buzzer in the vicinity of the pin which is formed to the watch crystal, as this is naturally arranged at some distance from the fixed ends of the tongue and the support arm. For this LII reason, the contact pressure between the blade of the yoke and the support arm is relatively large, so that plastic deformations also occur here during operation.

SUMMARY OF THE INVENTION It was the object of the invention to improve an electromagnetic buzzer of the type mentioned at the outset in such a manner that it can be more easily adjusted than the above described known design and that the adjusted condition can be maintained during operation. For this purpose, according to the invention it is proposed that the buzzer be designed in such a manner that the first adjusting element (for adjusting the buzzer relative to the membrane) is in a contacting relationship with a movable end of the support arm on the opposite side of the electromagnet system from the fixed end of the support arm, and in that the second adjusting element (for adjusting the tongue relative to the electromagnet system) acts on the tongue through reduction means. Because of these features, it is much easier to adjust the buzzer according to the invention precisely, since both the adjustment of the first as well as of the second adjusting elements are reduced. Also eliminated is the problem of plastic deformation in the area of the second adjusting element, which occurs during operation as a result of the high contact pressure between the bridge of the known design and the support arm.

It is simplest if the reduction means are comprising a lever, one end of which is fixed relative to the supporting arm in the area of the fixed end of the tongue, whereby the second adjusting element is in a contacting relationship with its other end and is in an operative connection with the tongue between its ends.

There are several possibilities for avoiding the gap between tongue and electromagnet system being influenced by adjustment of the first adjusting system; two embodiments proposed in accordance with the invention utilize a characteristic of the above mentioned, known design, as they both provide a firmly clamped block arranged between support arm and tongue on the opposite side of the electromagnet system from the free end of the support arm.

In the first embodiment, the lever (which forms the reduction means) is located on the side of the support arm facing away from the electromagnet system, while the second adjusting element is in a contacting relationship with the supporting arm between the first adjusting element and the electromagnet system; in addition, a pin, extending through the support arm, is slidably located in the block roughly at right angles to the tongue; one end of this pin is in a contacting relationship with the lever and the other end with the tongue. Since the second adjusting element connects the free end of the lever with the support arm at a point which is located between the first adjusting element and the fixed end of the support arm, adjustment of the entire buzzer with the aid of the first adjusting element does not alter the gap between tongue and electromagnet system. Since, on the other hand, alteration of the second adjusting element is not transmitted to the tongue by means of the support arm and the block as a result of the slidable pin, alteration of the setting of the gap between tongue and electromagnet system does not result in alteration of the location of the support arm.

With this embodiment of the invention, it is advisable to design the ends of the pin spherically, as this reduces the contact pressure between the pin and the lever as well as between the pin and the tongue, and prevents plastic deformations during operation.

The design of the first variant also permits the block to be employed as the base element of the buzzer, and the watch to be attached to it, whereby it supports the support arm and the tongue.

In the second variant of the design according to the invention, in which the two adjusting possibilities are disconnected, the lever (forming the reduction means) is arranged between tongue and block, and the second adjusting element is in a contacting relationship with the block. If the block is viewed as being rigid, which is permissible within the scope of the invention, it can clearly be seen that an alteration of the setting of the second adjusting element, i.e., the location of the tongue relative to the electromagnet system, will not result in a change in the location of the support arm. If the fixed end of the support arm is now attached to the watch and the block is further attached to the support arm, an adjustment of the first adjusting element will cause the support arm to move relative to the membrane as a whole, including block and tongue, so that, in the same manner as with the above discussed first variant, it is possible to install the buzzer, pre-adjusted relative to the gap between tongue and electromagnet system, in the watch as a sub-assembly whereby it must then only be adjusted relative to the membrane with the aid of the first adjusting element.

In the second variant, it is practical to provide a lineshaped contacting relationship between lever and tongue in order to avoid excessively high contact pressures in this manner and plastic deformations during operation.

It is advisable to cover the pole of an electromagnet of the electromagnet system facing the tongue with a plastic film to avoid, especially, adhesion of the tongue to this pole.

Finally, it is advantageous to arrange an elastic element, especially in the form of an elastic block or a spring washer, between the free end of the support arm and the watch (e.g., a plate), and to design the first adjusting element as a screw extending through the support arm and the elastic element.

DRAWING Further characteristics and details of the invention can be seen from the enclosed claims and/or the drawings and the following description of four embodiments of the buzzer according to the invention, in which FIG. 1 shows a cross section through a first embodiment of a buzzer according to the invention, made at right angles to the dial of a wristwatch; and

FIGS. 2 to 4 show corresponding cross sections through three other, largely similar embodiments.

DESCRIPTION FIG. 1 shows a portion of a watch crystal 10, mounted in a support 12 and having a pin 14 formed on its inside, said pin 14 extending through a hole 16 in a dial 18. Watch crystal is most practically of plastic. Moreover, of the watch only a plate, designated 20 as a whole, is shown, to which the buzzer according to the invention is attached.

This plate has a mounting block 22 with a mounting flange 24, which serves to fix the mounting block to plate 20 by means of a screw 26. The mounting block has two holes 28 and 30; the former serves to fix a support arm 32 and a lever 34 to one side of mounting block 22 as well as a tongue 36 to the other side by means of a screw 38 and a threaded sleeve 40. Slidably arranged in the second hole 30 is a pin 42, whose ends are in a contacting relationship with lever 34 on one side and tongue 36 on the other. Also fixed to support arm 32 is an electromagnet system, consisting of an electromagnet comprising one or two coils 44 and a core 46 as well as two permanent magnets 48 and 50. This electromagnet system further includes an armature plate 52, which is fixed on tongue 36. The end surface of core 46 facing the anchor plate, which forms one pole of electromagnet 44, 46, is lined with a plastic film 54 in order to prevent the anchor plate, and thus tongue 36, from adhering to the electromagnet.

The movable end 32' of support arm 32 can be adjusted relative to the clock, in the illustrated case relative to plate 20, with the aid of a system adjusting screw 56, which engages a tapped hole 58 in plate 20. Also located between support arm 32 and plate 20 is a spring washer 60, serving as a return spring for the support arm.

The movable end 32 of support arm 20 also carries an indicated printed circuit board 62, which bears the oscillator circuit. This serves to excite electromagnet 44, 46 with the natural frequency of tongue 36, which is also the natural frequency or a whole-number multiple of the natural frequency of watch crystal 10.

The free end 34 of lever 34 can be adjusted relative to support arm 32 by means ofa tongue adjusting screw 64.

The entire buzzer can be pre-adjusted prior to installation in the wristwatch, with respect to both the gap between anchor plate 52 and one pole of electromagnet 44, 46. This adjustment is made with the aid of tongue adjusting screw 64. As a result of the arrangement of pin 42, the displacement of the free end 34' of lever 34 is transferred to tongue 36 greatly reduced, so that the tongue can'easily be adjusted very precisely relative to the electromagnet with the aid of tongue adjusting screw 64.

After the buzzer has been installed in the watch, the entire buzzer is adjusted relative to pin 14 of the watch crystal with the aid of system adjusting screw 56 in such a manner that tongue 36 strikes the pin sufficiently. Because of the fact that tongue adjusting screw 64 is screwed into support arm 32 between the electromagnet system and the point of contact of system adjusting screw 56, adjustment of the entire system with the aid of adjusting screw 56 does not result in any alteration of the previously set gap between armature plate 52 and electromagnet 44, 46; another factor in this is that the tongue adjustment is transmitted from lever 34 to tongue 36 by means of pin 42, which slidably arranged in the support arm and in mounting block 22, since in the illustrated design tightening system adjusting screw 56 also results in a slight displacement of mounting of mounting block 22. However this has no effect on the adjustment of the tongue relative to the electromagnet, since with tongue adjusting screw 64 in a certain position pin 42 maintains the constant clearance between tongue 36 and support arm 32, and thus between the tongue and the electromagnet system.

While in the embodiment of the design according to the invention shown in FIG. 1 mounting block 22 is fixedly attached in the watch, the embodiments shown in FIGS. 2-4 have a mounting block 22a and 2212 which is attached to a support arm 32a and can move with it. Since the embodiments according to FIGS. 2-4 are similar to one another and coincide largely with the embodiment according to FIG. I, only the differing parts shall be described below; individual parts not mentioned on the basis of FIGS. 2-4 are provided with the same reference numbers as the corresponding parts in FIG. 1; the differing parts also have the same reference numbers, however with the letters a, b

Instead of being mounted by means of a mounting flange of the mounting block, the entire buzzers of the embodiments according to FIGS. 2-4 are attached to plate a with support arm 32a by means of a screw 26a. Mounting block 22a has a slot 70, thus forming a lever 34a which replaces the lever 34 in FIG. 1. Its free end 340 is subject to the effect of a tongue adjusting screw 64a, which extends through a hole 72 in support arm 32a. The adjustment movement of this adjusting screw is again transmitted reduced to tongue 36 by lever 34a, thanks to a rib 74 which provides a lineshaped contacting relationship between lever 34a and tongue 36. According to FIG. 2, to the left of the rib mounting block 220 has a notch 76, which results in a constriction at the root of lever 34a, around which the lever can be swivelled with the aid of tongue adjusting screw 64a.

As indicated by the dash-dotted line in FIG. 2, lever 34a could also be a separate member and not part of mounting block 22a.

As a result of the fact that in this embodiment the mounting block moves with support arm 32a, adjustment of system adjusting screw 56 again does not result in alteration of the gap between anchor plate 52 and electromagnet 44, 46, so that tongue 36 can be adjusted relative to the electromagnet system with the aid of adjustment screw 64a prior to the installation of the buzzer in the watch.

The embodiment shown in FIG. 3 differs from that according to FIG. 2 only in that lever 34b is designed as a separate member in the form of a stamped strip of sheet metal and in that the return spring for support arm 32a is in the form of a resilient block 60a.

The simplest embodiment ofa lever forming a reduction for tongue adjusting screw 64a is shown by FIG. 4: In this embodiment, lever 34c simply has the shape of a plane strip of sheet metal, with another simple, but shorter strip of sheet metal 90 also being clamped between it and tongue 36. If lever 34c is adjusted with the aid of tongue adjusting screw 64a sheetmetal strip 90 transmits and reduces the adjustment path of adjusting screw 64a.

Thus, it is common to all embodiments that 1. the adjustment paths of the adjusting screws are reduced;

2. pre-adjustment of the buzzer relative to the clearance between tongue 36 and electromagnet 44, 46

is possible, since adjustment of the entire system relative to pin 14 with the aid of the system adjusting screw does not result in alteration of the gap between tongue and electromagnet;

3. the precise adjustment of the buzzer itself and adjustment relative to pin 14 is not altered during operation.

This last advantage results from the fact that the entire system is not adjusted with the aid of a blade, but with the aid of system adjusting screw 56, and that the elements serving to adjust tongue 36 relative to electromagnet 44, 46 areless subject to plastic deformation during operation. In the first embodiment, pin 42 has spherical ends for this purpose; in the second embodiment according to FIG. 2, the conical end oftongue adjusting screw 64a engages a correspondingly shaped recess in lever 34a, and in the embodiments according to FIGS. 3 and 4, tongue adjusting screw 64a has a spherical end.

We claim:

I. In an electromagnetic buzzer for a watch. said buzzer of the type having a membrane with associated projecting pin means, an electromagnet system, a support arm carrying the electromagnet system, one end of which support arm is fixed to the watch and the other movable end of which can be adjusted relative to said pin means, and a tongue clamped on one end and arranged to be excited to oscillate by the electromagnet system and strike said pin means, the improvement comprising:

first adjusting means on said movable end of the support arm opposite the electromagnet system for positioning said support arm relative to said pin means,

second adjusting means acting near the clamped end of the tongue for positioning the tongue relative to the electromagnet system, said second adjusting means acting through reducation means.

2. The buzzer set forth in claim 1, wherein one pole of an electromagnet of said electromagnet system facing the tongue is covered with plastic film.

3. The buzzer set forth in claim I, wherein an elastic element, especially in the form of an elastic block or a spring washer, is arranged between the movable end of the support arm and the watch, and in that the first adjusting element is a screw extending through the support arm and said elastic element.

4. The buzzer set forth in claim 1, wherein said reduction means comprises a lever, one end of which is fixed relative to the supporting arm in the area of the fixed end of the tongue and arranged so that the second adjusting means is in a contacting relationship with its other end and is in an operative connection with the tongue between the ends of the tongue.

5. The buzzer set forth in claim 4 further having a fixedly clamped block arranged between support arm and tongue on the opposite side of the electromagnet system from the movable end of the support arm, characterized in that the lever is located on the side of the support arm facing away from the electromagnet system, in that the second adjusting element is in a contacting relationship with the support arm between the first adjusting element and the electromagnet system, and including a pin slidably located in said block which extends at roughly right angles to said tongue and extends through the support arm, with one end of the pin in a contacting relationship with the lever and the other end with the tongue.

6. The buzzer set forth in claim 5, wherein the ends of said pin are spherical.

7. The buzzer set forth in claim 5, characterized in that said block is attached to the watch and supports the support arm and the tongue.

8. The buzzer set forth in claim 4, having a firmly clamped block arranged between support arm and tongue on the side of the electromagnet system facing away from the movable end of the support arm,

wherein said lever is arranged between said tongue and said block and in that said second adjusting element is in a contacting relationship with said block.

9. The buzzer set forth in claim 8, wherein the fixed end of the support arm is attached to the watch and that the block is attached to the support arm.

10. The buzzer set forth in claim 8, wherein said lever is in a contacting relationship with the tongue along a line.

11. The buzzer set forth in claim 8, wherein said block defines a slot forming the lever.

12. The buzzer set forth in claim 8, wherein the lever is a section firmly clamped between block and tongue.

13. The buzzer set forth in claim 8, wherein the lever is a flat strip of sheet metal which is clamped between block and tongue together with a shorter strip of sheet metal located between it and the tongue.

14. The buzzer set forth in claim 8, wherein said second adjusting element is a screw for which said block has a thread, and in that the screw is accessible through a hole in the support arm or engages therethrough.

15. The buzzer set forth in claim 14, wherein said screw is in a contacting relationship with the lever via a spherical end. 

1. In an electromagnetic buzzer for a watch, said buzzer of the type having a membrane with associated projecting pin means, an electromagnet system, a support arm carrying the electromagnet system, one end of which support arm is fixed to the watch and the other movable end of which can be adjusted relative to said pin means, and a tongue clamped on one end and arranged to be excited to oscillate by the electromagnet system and strike said pin means, the improvement comprising: first adjusting means on said movable end of the support arm opposite the electromagnet system for positioning said support arm relative to said pin means, second adjusting means acting near the clamped end of the tongue for positioning the tongue relative to the electromagnet system, said second adjusting means acting through reducation means.
 2. The buzzer set forth in claim 1, wherein one pole of an electromagnet of said electromagnet system facing the tongue is covered with plastic film.
 3. The buzzer set forth in claim 1, wherein an elastic element, especially in the form of an elastic block or a spring washer, is arranged between the movable end of the support arm and the watch, and in that the first adjusting element is a screw extending through the support arm and said elastic element.
 4. The buzzer set forth in claim 1, wherein said reduction means comprises a lever, one end of which is fixed relative to the supporting arm in the area of the fixed end of the tongue and arranged so that the second adjusting means is in a contacting relationship with its other end and is in an operative connection with the tongue between the ends of the tongue.
 5. The buzzer set forth in claim 4 further having a fixedly clamped block arranged between support arm and tongue on the opposite side of the electromagnet system from the movable end of the support arm, characterized in that the lever is located on the side of the support arm facing away from the electromagnet system, in that the second adjusting element is in a contacting relationship with the support arm between the first adjusting element and the electromagnet system, and including a pin slidably located in said block which extends at roughly right angles to said tongue and extends through the support arm, with one end of the pin in a contacting relationship with the lever and the other end with the tongue.
 6. The buzzer set forth in claim 5, wherein the ends of said pin are spherical.
 7. The buzzer set forth in claim 5, characterized in that said block is attached to the watch and supports the support arm and the tongue.
 8. The buzzer set forth in claim 4, having a firmly clamped block arranged between support arm and tongue on the side of the electromagnet system facing away from the movable end of the support arm, wherein said lever is arranged between said tongue and said block and in that said second adjusting element is in a contacting relationship with said block.
 9. The buzzer set forth in claim 8, wherein the fixed end of the support arm is attached to the watch and that the block is attached to the support arm.
 10. The buzzer set forth in claim 8, wherein said lever is in a contacting relationship with the tongue along a line.
 11. The buzzer set forth in claim 8, wherein said block defines a slot forming the lever.
 12. The buzzer set forth in claim 8, wherein the lever is a section firmly clamped between block and tongue.
 13. The buzzer set forth in claim 8, wherein the lever is a flat strip of sheet metal which is clamped between block and tongue together with a shorter strip of sheet metal located between it and the tongue.
 14. The buzzer set forth in claim 8, wherein said second adjusting element is a screw for which said block has a thread, and in that the screw is accessible through a hole in the support arm or engages therethrough.
 15. The buzzer set forth in claim 14, wherein said screw is in a contacting relationship with the lever via a spherical end. 